This invention relates to a method for constructing large signboard posters, and specifically to a method for constructing posters adaptable for use in large signboards where back-lighting is used to create an illuminated poster image and thereby provide an enhanced visual effect.
In the field of outdoor advertising as it relates to large billboards the typical and preferred method of applying a very large poster to a billboard is to apply it in sections or sheets. Each section is typically glued or pasted to the billboard surface by a worker skilled in this field using long handled brushes and other tools for this purpose. The edges of adjacent sections are reasonably carefully aligned while the adhesive material is still in an unset condition so that adjacent sections may be moved about over the billboard. The number of sheets applied in this manner varies with the relative size of the billboard, but it is not unusual to apply a dozen or more sections to a billboard in the size range of ten feet by twenty-four feet or larger. Billboard posters applied in this manner are typically made from poster paper which has very little structural strength itself, but which when adhered to a billboard surface will withstand normal weathering and exposure to the elements for a number of months.
Billboards and posters constructed according to the aforementioned procedure may be illuminated for nighttime display, but such illumination usually takes the form of directional lighting illuminating the front surface of the billboard from a position above or below the billboard surface so as to create a minimum line of sight interference with the poster itself. Such lighting enhances the advertising value of the billboard by increasing the number of hours per day that the billboard serves as an advertising medium.
It has been known that a number of advantages can be had by lighting a billboard from the rear surface, one of which is the obvious advantage of being able to house the electrical circuits and lighting fixtures within the billboard structure itself to avoid exposure to the elements and to minimize damage from weather and vandalism. Further, a back-lighted billboard presents a more pleasing image which is somewhat softer to view and is more likely to draw attention to the poster displayed on the billboard. Prior art poster images which have utilized back-lighted signboards have most often been constructed using photographic techniques on film, usually utilizing only a single sheet of material for this purpose. Since it has not been possible to create very large single sheet photographic images such back-lighted billboards have typically been rather small in size and in no way approaching the size of a standard outdoor billboard. When larger billboards have been attempted to be constructed using a plurality of photographic images in edge alignment to create a large poster image, the problem of providing imperfect edge alignment has resulted in very visible lines of light escaping between adjacent photographic sections. These edge lines result from the back-lighting shining directly through the billboard surface, and they tend to be very distractive of the overall image and produce a resultant lower quality and less pleasing poster effect.